Mitral valve score for assessment of valve anatomy and suitability for Percutaneous

Balloon Mitral Valvuloplasty (PBMV)

Dr Amit KumarSenior Resident, Department of Cardiology

R.N.T. Medical CollegeUdaipur,India

• Percutaneous balloon mitral valvuloplasty (BMV) was introduced in 1984 by Inoue et al, for treatment of selected patients with mitral stenosis. (J Thorac Cardiovasc Surg 1984;87:394-402)

• BMV – treatment of choice for majority of patients with moderate or severe rheumatic mitral stenosis (ACC/AHA guidelines)

• Success of BMV depends on appropriate patient selection.

• Several echocardiographic scores have been proposed to optimize patient selection and to predict outcome.

• Wilkins score (MGH score/Boston score/Abascal score). (Br Heart J.1988;60:299-308)

• Commissural calcium score. ( J Am Coll Cardiol 1997;29:175-80)

• Cormier score ( Echocardiographic gouping/ Iung-cormier score) (Circulation.1996;94:2124-30)

• Real-time 3D echocardiography score (RT 3DE score/ Anwar score) (J Am Soc Echocardiogr.2010;23:13-22)

• Chen et al score (J Am Coll Cardiol 1989;14(7):1651–8)

• Reid score (Circulation. 1989;80 (3):515–24)

• Nobuyoshi score (Circulation. 1989;80 (4):782–92)

• Commissural fusion is the requisite lesion for BMV to be effective because commissural splitting is the dominant mechanism by which MV stenosis is relieved in this technique.

• Pathological process of RF causes progressive leaflet thickening, calcification, commissural and/or chordal fusion- thus resulting in narrowing of MV orifice. (Ann Intern Med 1972;77:939-75)

• Accordingly, four types of MS have been described (Circulation. 1956; 14:398-406)

1) Commissural – 31% 2) Cuspal – 15.5% 3) Chordal – 8.5% 4) Combined – 45%

• Despite the expertise in percutaneous mitral commissurotomy (PTMC), mitral regurgitation remains a major complication. ( U.A. Kaul et al. “Mitral regurgitation following PTMC: a single center experience,” Journal of Heart Valve Disease, vol.9,no.2,pp262-268,2000)

• Incidence of severe MR after PTMC in the literature varies b/w 1.4% and 7.5% ( Hernandez et al. American Journal of Cardiology,vol.70,no.13,pp.1169-1174,1992) ; ( Padial et al. JACC,vol.27,no.5,pp.1225-1231,1996)

• Mild MR after PTMC occurs in 40% pt. – usually d/t commissural splitting (Circulation1991;84:1669-79)

• Severe MR after PTMC is typically caused by leaflet rupture and less frequently by subvalvular apparatus damage (Am J Cardiol 1988;62:264-9)

• Studies of surgically excised mitral valves of pt. who developed sev.MR after PTMC have consistently shown three anatomic characterstics

1) Heterogeneously thickened MV with thick areas coexisting with thin or almost normal zones,

2) Severe fusion, thickening and shortening of subvalvular apparatus,

3) Calcium in one or both commissures

Kaplan JD, Isner JM, Karas RH, et al. In vitro analysis of mechanisms of balloon valvuloplasty of stenotic mitral valves. Am J Cardio11987;59:318-23; . Sadee AS, Becket AE. In vitro dilatation of mitral valve stenosis: the importance of subvalvular involvement as a cause of mitral valve insulfficiency. Br. Heart J 1991;65:277-9

•MR-Echo Score –

Predictor of developing significant MR following PTMC

Wilkins score

• Most commonly used

• 2D TTE assessment of mitral valve -> leaflet thickening, leaflet mobility, calcification and subvalvular involvement .

• Each feature is graded on a scale of 1 to 4, yielding a maximal score of 16 and minimal score of 4.

• Leaflet thickening -PLAX

• Restricted mobility –PLAX

• Chordal thickening, shortening and fusion –PLAX and A4C

• Superimposed calcification

Wilkins score

• In 1988, Wilkins and coworkers found that total MV echocardiographic score was the best predictor of immediate outcome after BMV. (Br Heart J.1988;60:299-308)

• High score (advanced leaflet deformity) was associated with a suboptimal outcome while a low score (a mobile valve with limited thickening) was associated with an optimal outcome. (Br Heart J.1988;60:299-308)

• All patients with score < 9 had optimal results and those with score >11 had suboptimal results. Score failed to predict outcome in those with scores of 9 to 11. (Br Heart J.1988;60:299-308)

• MV morphology is considered favorable for BMV if total score <=8.

• A score >8 does not preclude BMV, but is associated with less optimal results

• Wilkins score – not able to predict which patients will develop significant MR after PTMC.

Abascal MV, Wilkins GT, Choong CY, Block PC, Palacios I, Weyman AE. Mitral regurgitation after percutaneous balloon mitral valvuloplasty in adults: evaluation by pulsed Doppler echocardiography. J Am Coll Cardiol 1988;11:257- 63.

•Leaflet Mobility: 4 – No or minimal forward movement of the leaflets.•Subvalvular Thickening: 2-3-Thickening of chordal structures up to one-third of the chordal length possibly to distal third of the chords.•Leaflet Thickening: 4 – Considerable thickening of all leaflet tissue (>8-10mm).•Calcification: 4 – Extensive brightness throughout much of the leaflet tissue.

Wilkins score: 14

Wilkins Score = 12Mobility – valve moves forward in diastole, moves mainly from base3 points

Subvalvular Thickening – thickening of chordal structures extending into distal 1/3rd of the chordal length 3 points

Thickening – extends through the entire leaflet3 points

Calcification – Brightness extending into the mid-portion of the leaflets3 points

Total score = 12

Limitations of wilkins score

• Assessment of commissural involvement not included.

• Limited in ability to differentiate nodular fibrosis from calcification.

• Doesn’t account for uneven distribution of pathologic abnormalities.

• Frequent underestimation of subvalvular disease.

• Doesn’t use results from TEE or 3D echo

Commissural Calcification Score

• Extent of commissural calcification is quantified – each half commissure (anterolateral & posteromedial) is given a score of 1 for detection of high-intensity bright echoes.

• Ranges from grade 0 to grade 4.

• Commissural calcification is a strong predictor of adverse outcomes of BMV as well as of the occurrence of severe MR as a major complication of BMV. (J Am Coll Cardiol 1996;27:1225-31)

• Influence of commissural score – most evident in pt with wilkins score <8; not significant in pt with wilkins score >8.

Commissural Calcification Score

Cormier Score

• Derived from a study which assessed late functional results after successful PTMC and its determinants ( Iung et al, J Am Coll Cardiol1996;27:407-14)

• Based on echocardiographic and fluoroscopic assessment of valve mobility, subvalvular disease and leaflet calcification

• By multivariate analysis, the independent predictors of good functional results were echocardiagraphic group (p = 0.O1), functional class (p = 0.02) and cardiothoracic index (p = 0.005) before the procedure and valve area after the procedure (p=0.007).

Iung et al, J Am Coll Cardiol 1996;27:407-14

Cormier Score

• Wilkins score in the range of 7-9 correlates with echocardiographic group 1.

• a range of 8-12 correlates with echocardiographic group 2.

• a range of 10-15 correlates with echocardiographic group 3

Iung et al, J Am Coll Cardiol 1996;27:407-14

RT-3DE score

• Based on real time 3D TTE

• Highly reproducible, good interobserver and intraobserver agreement

RT-3DE score

• Incidence and severity of post- procedural MR were associated with high RT-3DE score

• Another 2DE score by Chen et al. is a modified Wilkins score parameter for subvalvular thickening according to the involved segment of chordal length: (1) if less than 1/3, (2) if more than 1/3, (3) if more than 2/3, and (4) if involved the whole chordal length with no separation.

• Reid score includes leaflet motion, leaflet thickness, subvalvular disease, and commissural calcium.

• Leaflet motion was expressed as a slope by dividing the height (H) by the length (L) of doming of anterior leaflet. Leaflet thickness was expressed as the ratio between the thickness of the tip of MV and thickness of posterior wall of aortic root.

• The score was assigned as 0 for mild affection, 1 for moderate , and 2 for severe affection

Nobuyoshi Score

MR- Echo Score (Padial et al. JACC1996;27:1251-31)

• Total MR-Echo score – only independent predictor of significant MR following PTMC using Inoue technique ( Elasfar et al , Cardiology Research and Practice vol.2011)

• Total MR-echo score of 7 Positive predictive value 97.7% (Padial et al. JACC1996;27:1251-31)

Limitations of scoring system

• No individual scoring system is superior to another. Complement each other for comprehensive

echocardiographic assessment.

• All scoring system have got variable reproducibility

• All scores are semiquantitative

• Subvalvular disease is frequently underestimated

Ideal echo scoring system

• Inclusion of all points that proved to predict and affect the BMV outcome via large study.

• High reproducibility and reliability

• Easily applicable and interpretable by most cardiologists within a reasonable time.

• Validation in large studies that include pt with different age groups (not only young)

• Global and segmental evaluation of each MV apparatus component seperately to localize the deformity in a specific portion of MV apparatus.

• Unified for both TTE & TEE approaches

Thank you…